Is 3 TDS good enough for SPS?

[downhillbiker]

Is 3 TDS after an RO/DI unit good enough to keep SPS corals? found a unit i want that does 300 TDS to 3 TDS, and want to know if that is good enough.

I only have 30-40 TDS tap water, but will eventually move, and don't know what my water will be like then.

[Buckeye Hydro]

about 3 ppm TDS is generally when folks think about changing their resin.

Russ

[emoore]

You should want 0 TDS. My tap is at 150 ppm TDS and my RO/DI is 0.

[kar93]

You should just buy an RO/DI from Marine Depot or somewhere like that and you will be guaranteed 0TDS.

[snorvich]

0 TDS. No compromises.

[ConsultantERP]

Your sps will never know the difference. 3 TDS equates to about a speck of dust in a swimming pool, and yes it probably means its time to change a filter somewhere.

[sirreal63]

<a href=showthread.php?s=&postid=12281567#post12281567 target=_blank>Originally posted</a> by ConsultantERP
Your sps will never know the difference. 3 TDS equates to about a speck of dust in a swimming pool, and yes it probably means its time to change a filter somewhere.


I agree completely!!! How long is 0 tds water going to remain 0 tds? About as long as it takes to put it into whatever container you use to store or mix water in. If anyone doubts this please measure the tds of the water you store prior to adding salt. Yes you want to start with as clean of water possible but there is no need in going nazi over it.

[jakaufman]

<a href=showthread.php?s=&postid=12281815#post12281815 target=_blank>Originally posted</a> by sirreal63
I agree completely!!! How long is 0 tds water going to remain 0 tds? About as long as it takes to put it into whatever container you use to store or mix water in. If anyone doubts this please measure the tds of the water you store prior to adding salt. Yes you want to start with as clean of water possible but there is no need in going nazi over it.

agreed. id actually be interested in people's TDS readings coming out of their water storage pre-salt.

[miwoodar]

The real problem isn't the TDS, it's what freaky stuff might be leaching off of spent DI resins. You never know if two not-so-bad things might have come together to make something much worse.

[sirreal63]

Of course we don't have all the information from the OP on the unit so giving general advice is all we can do.

I agree with Mike about what is leaching off but to carry it further what effect does mold spores, pollen, airborne contaminants have on our "pure" water? These same airborne particles settle in our tanks no matter how "pure" our water is to begin with. Start with clean water but don't expect it to stay that way.

[downhillbiker]

here is the link to the unit:
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&rd=1&item=110240097533&ssPageName=STRK:MEWA:IT&ih=001

heres a link to another unit made by the same company that does 0 tds:
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&rd=1&item=110239833989&ssPageName=STRK:MEWA:IT&ih=001

Is it really worth it? I mean how much does that 3 tds really matter?

Dont tell me I need to buy a unit from marinedepot or drsfosterandsmith for $300 thats BS. This unit for $100 will work just fine. I feel confident in their AMERICAN MADE unit.

I just dont know if I should go with the cheaper one, or if its really necessary to buy the 0ppm filter.

[mixed_reefer]

I guess its a step up from tap.... Dont kid yourself that thing is 98% chinese made. You can find much better units at decent prices and you would be much happier. Dont skimp on water, its a large part of your tank.

[sirreal63]

Here is what you will find with that unit. It will work fine for a while but the tds will creep up. You will eventually end up replacing the filters in it with better quality products. I bought a cheapo unit to begin with and switched out the guts with quality stuff and it does make a difference. I paid more than the price of a good quality unit by the end of a year.

Get a unit from Buckeye or The Filter Guys and spend the money once, not multiple times. There is a point when being cheap makes no sense...I had to learn it the hard way. Learn from others mistakes.

[Randy Holmes-Farley]

I think we need to be careful what we are saying here. If all you did was take out 99% of what was there (300 ppm TDS to 3 ppm TDS). most (but not all) tap water will then be OK. But that is definitely not what happens when using an RO/DI.

If you have an RO/DI that initially gives 0 ppm TDS, and then later it becomes depleted and the TDS slowly rises, you are not just getting very slightly impure fresh water. You are getting water that is GREATLY enriched in those things which are most easily displaced form a DI resins as more salts come into it.

Unfortunately for reefers, those are often going to be ammonia and silicate. When my DI recently depleted, the limewater I made from it stank of ammonia. That would not happen at normal concentrations, but does when greatly enriched in the first effluent to rise above 1 ppm TDS.

So IMO, it is important to replace a DI as soon as the TDS rises. :)

I discuss that here:

Reverse Osmosis/Deionization Systems to Purify Tap Water for Reef Aquaria
http://reefkeeping.com/issues/2005-05/rhf/index.htm

[AZDesertRat]

Spend a little more money and do it right the first time. $161 will get you a very good RO/DI unit that will get you where you need to be, www.buckeyefieldsupply.com 75 GPD premium system. It comes with everything you will ned to get up and running including a TDS meter and pressurte gauge.
The units you linked to are very poor quality units and will never perform for any length of time.

When buying an RO/DI look at things like who makes the RO membrane (notice that one does not say?) , who makes the carbon block filter and is it in the 0.6 or 0.5 micron range, does it include a pressure gauge, handheld TDS meter, full sized vertical refillable 20 oz DI filter (note that one does not this) etc. If thye don't tell you who makes it chances are its a low quality imported knockoff.

[oscarsdad608]

I have the unit you are looking at. After 6 months I still have 0ppm. It does not come with a tds or any extras. I have bought different refills and was not happy with there response to some of my ?. I would go with a different unit.

[thecichlidpleco]

Is regular flushing what keeps the TDS down? Or when the TDS rises even with flushing the time when resin and such needs to be replaced?

[Randy Holmes-Farley]

Yes, with one D you replace the DI as soon as the effluent rises to 1 ppm TDS.

If you have a dual DI unit (like the Spectrapure unit I have), then you can use even more of the first DI, until it only takes out about half of the TDS in the RO membrane effluent, then toss it and swap the second one into the first slot and put a new one in the second slot. That way each unit gets more use, but the TDS never rises above 0 ppm TDS. :)

[craftedpacket]

I bought a non cheap unit from airwaterice. It worked well for a while then I was getting really high TDS out of my membrane. With advice from AZ and buckeye I replaced all my filters and membrane...I just recently replaced all my filters again moving to a pleated sediment filter and the highest quality carbon filters they had at buckeye. My tap water is 700-900 PPM and I get 15ppm out of my membrane and 0 out of my DI. I switched to non color changing DI because of recommendations to do so and installed an inline dual TDS meter.

AZ and Buckeye know their stuff so I would recommend taking their advice. Save yourself the trouble now because you don't want to be fighting algae the rest of your tanks life.

[downhillbiker]

<a href=showthread.php?s=&postid=12284272#post12284272 target=_blank>Originally posted</a> by thecichlidpleco
Is regular flushing what keeps the TDS down? Or when the TDS rises even with flushing the time when resin and such needs to be replaced?

so which unit is it? the one for $100 shipped or the one that is $130 shipped. the first or second link? so why dont you like it? the customer service? or is there some problem with the unit.

[craftedpacket]

Thats a pretty cheesy looking DI cartridge if you ask me. I have never heard of those membranes. Most people that know RO recommend filmtec or spectropure membranes.

[craftedpacket]

with the close ups of the parts the fittings and valves look really cheap compared to a more expensive unit. The parts such as the auto-shutoff valve look cheap compared to the parts on my system. IMO.

[Buckeye Hydro]

<a href=showthread.php?s=&postid=12283751#post12283751 target=_blank>Originally posted</a> by Randy Holmes-Farley
When my DI recently depleted, the limewater I made from it stank of ammonia.

Randy - do you have chloramines in your tap water?

[Randy Holmes-Farley]

Yes, I do. That is the source of the ammonia that I mentioned. :)

[virginiadiver69]

<a href=showthread.php?s=&postid=12284516#post12284516 target=_blank>Originally posted</a> by downhillbiker
so which unit is it?

Neither one.
Do yourself a favor, listen to the advice being given you and bite the bullet and spend the $150. Stay with thefilterguys, buckeyfeildsupply or spectrapure. Those eBay units are best for drinking water only.

[Curve]

I have that exact same unit that I have been using for about 6 months with no complaints. I have 425 plus ppm tap water and it gives me 1ppm reading out of the other side. I use it on reef with no problems and you can replace the membranes with the filmtecs when they need replacing.

[AZDesertRat]

Again any RO/DI should give you 0 TDS, at least for a short time.
The story though is in the RO only TDS. What is that number? This will tell you how good the membrane is since it does 98% of the work, the DI just polishes it off. The moral is better units use better membranes so you will get 0 TDS for much longer thus saving you money on DI resin replacements.
The other thing to look at is the quality of the prefilter and carbon block, cheap ones do not work as well and cause themembrane to fail sooner, again costing you more long term money.
Look at a RO/DI like a fine tool, spend wisely and get a good unit and it will serve you for years and years with little maintenance and cash outlay. Buy a cheap one and it nickles and dimes you to death from then on until you get frustrated and throw it away!

[thecichlidpleco]

I got the reef/residental 75 gpd and it is great for drinking water also, I would not go back to buying water.

[downhillbiker]

<a href=showthread.php?s=&postid=12289668#post12289668 target=_blank>Originally posted</a> by AZDesertRat
Again any RO/DI should give you 0 TDS, at least for a short time.
The story though is in the RO only TDS. What is that number? This will tell you how good the membrane is since it does 98% of the work, the DI just polishes it off. The moral is better units use better membranes so you will get 0 TDS for much longer thus saving you money on DI resin replacements.
The other thing to look at is the quality of the prefilter and carbon block, cheap ones do not work as well and cause themembrane to fail sooner, again costing you more long term money.
Look at a RO/DI like a fine tool, spend wisely and get a good unit and it will serve you for years and years with little maintenance and cash outlay. Buy a cheap one and it nickles and dimes you to death from then on until you get frustrated and throw it away!

The TDS reading after the RO only is from 300ppm to under 20ppm so that is about 95% of the cleaning done by RO unit. I appreciate everyone's advice, but I will be buying the unit and giving it a try.

I am down to this...my girlfriend freaks when I tell her the price, and I am lucky that she will let me get the cheap one. It's better than nothing right? And the one I am getting is a 0ppm filter, the difference is what DI media they use.

[HChellette]

Go for it b/c I am very happy with my unit.

[downhillbiker]

sounds good. i just bought it. it will work great.

100GPD 6 stage RO/DI (2x) DI, plus 3 replacement filters, and 2 replacement DI media, and its shipped to my door for $117. I think it will work great.

I am getting 2 DI units and 2 replacement DI media, so that should keep it clean, I will just keep rotating the back filter into the front slot, and replace media in old filter.

[kar93]

do you have a pic of the unit or a link

[sirreal63]

I hope it works for you long term. The cheapo unit I had went through DI like crazy because the membrane had a horrible rejection rate. I thought everything was fine until I checked the TDS and discovered why I was burning through DI. I highly suggest you invest in a TDS meter. Once you get ready to replace the membrane get a good one from BFS or The Filter Guys, it does make a difference.

I know you took offense at so many of us suggesting a better unit...there is a reason...we learned the hard way and hoped to prevent someone else from learning the hard way. It may have made you feel we are elitist but in reality it is because we care.

[snorvich]

Yes, I agree with above. I used to buy cheap until I realized it was more expensive in the long run.

[downhillbiker]

i understand. thanks guys. i just think that some units lack mechanically or in design, but i am very mechanically inclined and build much of my own stuff and design my own parts, when cheap ones break.

Yes thats a headache sometimes, but...
1. It makes me more familiar with the unit.
2. When I do fix it it's stronger, and works better than if I had bought the expensive unit.

The link to the actual site won't work, so here's the same one on ebay.
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&Item=150225033009&Category=20684&_trksid=p3907.m29

[AZDesertRat]

You will find you will spend much more to make it right than what you would have spent initially on a better unit. Good filters cost money.
Did you get a handheld TDS meter with the unit? If not how are you going to troubleshoot it? Same goes for an inline pressure gauge. Just the additional cost of those two things alone makes the Buckeye 75 GPD Premium a much better value, not even mentioning better prefilter, top name carbon block, Dow Filmtec name brand RO membrane, RO bypass valve, adjustable flow restrictor..... and all at only $161. I think you are making a big mistake. Price alone is not what you should be looking at, look at long term cost of ownership and water quality not saving a nickel today to spend much more tomorrow in upgrades and replacements.